Experimental demonstration of a Rayleigh-scattered laser guide star at 351 nm

A commercially manufactured excimer laser was used to project a focused laser beam into the atmosphere to altitudes in the range of 10 to 30 km. Rayleigh-backscattered light from a slice of the illuminated column, when imaged in a ground-based telescope, produced an image that is essentially identical to that of a natural star. This experiment demonstrates the ease of producing bright and sharply focused laser guide stars at 351 nm. Such laser guide stars are ideal for guiding astronomical telescopes equipped with adaptive optics.